System and method for providing an early notification when paging a wireless device

ABSTRACT

A system and method for a server to provide an early notification to a target group devices when paging a wireless device during a push-to-talk (PTT) communication. When a wireless device is ready to transmit a PTT communication, a message is sent from the wireless device to a server that then sends an early PING message to a base station while processing a call request message from the wireless device. After processing the call request message, the server sends an announce message to the base station. On receipt of the PING message, the base station sends a paging message to all targeted devices while processing the announce message. The early PING message causes a communication channel to be established between a targeted device and the base station, and the communication channel can then be used by the announce message with less set-up time.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/353,416, filed Feb. 13, 2006, now patented as U.S. Pat. No. ______,issued ______, which is hereby incorporated by reference in itsentirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to wireless telecommunications,and more specifically, relates to a system and method for reducing thewait time at telecommunication originating wireless device during apush-to-talk (PTT) communication.

2. Description of the Related Art

Technology advancement has made mobile telephones or wirelesscommunications devices inexpensive and accordingly ubiquitous. Aswireless telecommunication devices are manufactured with greaterprocessing ability and storage, they also become more versatile andincorporate many features including direct radio communicationcapability between two or a group of individual handsets. This directradio communication capability is commonly known as the push-to-talk(PTT) or “walkie-talkie” feature that allows a user with one handset tocommunicate with the device of a predefined set of members of a groupwithout dialing a destination telephone number.

In one version of a PTT system, a wireless telecommunication device,such as a wireless telephone handset, uses one single frequency for bothupward and downward communications with a remote PTT server, while in anormal wireless communication a wireless telephone uses two frequenciesfor communicating with the PTT server, one for outgoing and one forincoming communications. In one extant form, The PTT system requires theperson who is speaking to press a PTT button while talking and thenrelease it when done. Any listener in the group can then press theirbutton to respond. In this manner, the system determines which directionthe signal travels. In a typical configuration, when a user makes a callto a receiving party or a group of receiving parties using the PTTsystem, the user's handset first makes a request to a remote server byinforming the server it is ready to transmit. The remote PTT serververifies that no other party is using the communication channel, thatthe channel is available, and then assigns the channel to the user. Theuser's message is received by the server and the server sends themessage for each and every receiving party. After the message istransmitted to every receiving party, the channel is released and readyfor use by other parties.

During the process described above, usually there is a noticeable delaybetween the time a user presses a PTT button at his handset until thetime the user is allowed to input his audio message. The delay is causedby the network and server set-up to handle and relay the communication.The server will grant the floor to the user after the targeted deviceshave responded and are ready to receive the audio message. Though short,the delay can be annoying; especially today when people are expectingdirect telecommunications be as close to instantaneous as possible.

Therefore, it is desirous to have an apparatus and method that enables aserver to quickly dispatch a response to the wireless device and thewireless device to quickly establish a PTT communication in a PTTcommunication system. It is to such an apparatus and method the presentinvention is primarily directed.

SUMMARY OF THE INVENTION

The system and method according to the invention enables a server toprovide an early notification when paging a wireless device during apush-to-talk (PTT) communication. When a wireless device is ready totransmit a PTT communication, a message is sent from the wireless deviceto a server. The server then sends an early PING message to a basestation while processing a call request message from the wirelessdevice. After processing the call request message, the server sends anannounce message to the base station. On receipt of the PING message,the base station sends a paging message to all targeted devices whileprocessing the announce message. The early PING message causes acommunication channel be established between a targeted device and thebase station, and the communication channel can then be used by theannounce message with less set-up time.

In one embodiment, a method is provided for reducing queuing time for anactivity announcement message during a push-to-talk (PTT) communicationin a wireless communication network. The method includes receiving at aserver a first message invoking a PTT feature at the server from anorigination device, identifying at least one targeted device for the PTTcommunication from the origination device, transmitting a second messagewith a header and an empty message body from the server to the at leastone targeted device, and transmitting the activity announcement messagefrom the server to the at least one target device. The second message issent by the server to the at least one target device before the activityannouncement message.

In another embodiment, a server is provided that is capable of handlingpush-to-talk (PTT) communications in a communication network, whereinthe server, upon receiving a call request message for a PTTcommunication, identifies at least one target wireless device, transmitsa testing message to the at least one target wireless device beforeallocating resources to the PTT communication, and transmits an announcemessage to the at least one target wireless device after allocating theresources to the PTT communication.

In yet another embodiment, a system is provided for reducing queuingtime for an activity announcement message during a push-to-talk (PTT)communication in a wireless communication network. The system includes aserver, a base station, and a user device. The server communicates withthe wireless communication network and selectively transmits to a userdevice a plurality of messages. The base station communicates with theserver and the user device and relays message therebetween. The userdevice is capable of communicating with the server through the basestation. The server, upon receiving a call request message from the userdevice for a PTT communication, identifies at least one target wirelessdevice, transmits a testing message to the at least one target wirelessdevice before allocating resources to the PTT communication, andtransmits an announce message to the at least one target wireless deviceafter allocating the resources to the PTT communication.

The present system and methods are therefore advantageous as they enablea wireless communication device to efficiently transmit data and/oraudio packets to a server during a PTT communication, thereby lesseningsetup delay. Other advantages and features of the present invention willbecome apparent after review of the hereinafter set forth BriefDescription of the Drawings, Detailed Description of the Invention, andthe Claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a prior art communication network.

FIG. 2 is a diagram representing prior art interactions between theserver and wireless devices during a set up process for a PTTcommunication.

FIG. 3 is a prior art message flow between wireless devices and theserver during the set up process for the PTT communication.

FIG. 4 is an exemplary embodiment of a message flow between wirelessdevices and the server during the set up process for the PTTcommunication.

FIG. 5 is a flow chart for an exemplary embodiment of a server process.

FIG. 6 is a flow chart for an exemplary embodiment of a base stationprocess.

DETAILED DESCRIPTION OF THE INVENTION

In this description, the terms “communication device,” “wirelessdevice,” “wireless communications device,” “PTT communication device,”“handheld device,” and “handset” are used interchangeably, and the terms“channels” and “groups” are used interchangeably. The term “application”as used herein is intended to encompass executable and nonexecutablesoftware files, raw data, aggregated data, patches, and other codesegments. The term “communication channel” refers to any voice or datapath in a telecommunication or computer network in digital or analogformat. As used herein, the term “exemplary” only indicates that what isshown is an example, and does not indicate a preferred embodiment orotherwise indicate any degree of preference. Further, like numeralsrefer to like elements throughout the several views, and the articles“a” and “the” include plural references, unless otherwise specified inthe description.

In overview, a system and method according to the invention shortens thedelay between the time a user presses a PTT button and the time the PTTserver grants “the floor” to the user by enabling an early PING messagebe sent to the targeted wireless devices. FIG. 1 depicts a prior artcommunication network 100. The communication network 100 includes one ormore communication towers 106, each connected to a base station (BS) 110and serving users with communication device 102. The communicationdevice 102 can be cellular telephones, pagers, personal digitalassistants (PDAs), laptop computers, or other hand-held, stationary, orportable communication devices that support push-to-talk (PTT)communications. The commands and data input by each user are transmittedas digital data to a communication tower 106. The communication betweena user using a communication device 102 and the communication tower 106can be based on different technologies, such code division multipleaccess (CDMA), time division multiple access (TDMA), frequency divisionmultiple access (FDMA), the global system for mobile communications(GSM), or other protocols that may be used in a wireless communicationsnetwork or a data communications network.

The PTT communications are transmitted through data packets over thecommunication network 100. The wireless communication device 102 sendsand receives audio data packets on an assigned communication channel andcontrol data are sent and received through a data channel. The datapackets from each device is sent from the communication tower 106 to abase station (BS) 110, and forwarded to a mobile switching center (MSC)114, which may be connected to a public switched telephone network(PSTN) 118 and the Internet 120. The MSC 114 may be connected to aserver 116 that supports the PTT feature in the communications network100. Optionally, the server 116 may be part of the MSC 114. The server116 may also suppress transmission of PTT communication to a particularwireless device upon request from the device requesting not to becontacted. The data packets are forwarded by the server 116 to thereceiving wireless device 102 where an audio stream will be constructedbased on the data in the data packets. In an alternative embodiment (notshown), the MSC 114 may not needed in a data-only network. The datapackets are sent by the BS 110 to a packet data serving node and/orother servers for processing. The data packets are transmitted betweenthe wireless device 102 and the BS 106 according to a predefinedprotocol such as Real-time Transport Protocol (RTP), Transfer ControlProtocol/Internet Protocol (TCP/IP), User Datagram Protocol (UDP)/IP, orother suitable protocols.

An originating wireless device 102, when ready to engage in a PTTcommunication, sends a call message through the base station 110 to theserver 116. The server 116 sends an announce message to the base station110. The announce message is queued at the base station 110 until thetargeted wireless device 102 is located. The base station 110 uses apage message to locate the targeted wireless device 102. After receivinga response from the targeted wireless device 102, the base station 110delivers the announce message to the targeted wireless device 102. Thetargeted wireless device 102 acknowledges the announce message, and thisacknowledgement message is forwarded by the base station 110 to theserver 116. After confirming the targeted wireless device 102 isavailable, the server 116 sends a status message to the originatingwireless device 102. The originating wireless device 102 can then startto transmit subsequent audio communications.

FIG. 2 is a simplified diagram 200 representing interactions between theserver (also known as the group communication server) 116 and wirelessdevices 102, 206, 208 during a PTT communication process. The basestations 110 are omitted from FIG. 2. A communication does not occurbetween an initiating wireless device 102 and a server 116 until a useractivates the PTT feature, typically by pressing a PTT button. After theuser activates the PTT feature, the wireless device 102 sends a messageto the server 116 indicating it is ready to transmit a PTT message. Uponreceiving the message from the wireless device 102, the server 116determines the target wireless devices 206, 208 to which the PTTcommunication is directed and pages the wireless devices 206, 208.

FIG. 3 is a prior art diagram 300 illustrating the message flow in acommunication network when setting up a PTT communication. Theoriginating wireless device (user device) 302 sends a call requestmessage through wireless communication to the base station 304, whichforwards the call request message to the server 306. When the server 306receives a call request message, the server 306 executes a variety oftasks before sending an announce message to the target wireless devices.The server 306 identifies the target wireless device, checks for callrestrictions for the target wireless device, selects a vocoder and amedia host for the PTT communication, checks whether it is a group call,and allocates other related resources as necessary.

After performing all the tasks described above, the server 306 sends anannounce message to the base station 308 that serves the target wirelessdevice 310. Before delivering the announce message to the targetwireless device 310, the base station 308 queues the announce messageand pages the target wireless device 310. When a page response isreceived by the base station 308, the base station 308 sets up a datachannel between the base station 308 and the target wireless device 310.After the data channel is established between the base station 308 andthe target wireless device 310, the base station 308 transmits theannounce message to the target wireless device 310. The target wirelessdevice 310 sends an acknowledgment message back to the base station 308indicating it is available for the PTT communication. The base station308 forwards the acknowledgment message back to the server 306. Afterconfirming the target wireless device 310 is available, the server 306grants the “floor” to the originating wireless device 302 by sending astatus message to the originating wireless device 302. The statusmessage is received and forwarded by the base station 304 to theoriginating wireless device 302. After the status message is received bythe originating wireless device 302, the originating wireless device 302generates an audible indication to the user indicating the wirelessdevice and the network are ready for the PTT communication.

The time delay from the time when the user pushes the PTT button untilthe audible indication is played to the user is a noticeable delay tothe user and this delay is greatly dependent on the queuing time 312 theannounce message is queued at the base station 308.

FIG. 4 is a message flow diagram 400 where the time delay is reduced byreducing the queuing time. The originating wireless device (user device)302 sends a call request message through wireless communication to thebase station 304, which forwards the call request message to the server306. When the server 306 receives the call request message, the server306 first identifies the target wireless device, and then checks forcall restrictions for the target wireless device. If the target wirelessdevice does not have any call restriction, i.e., the target wirelessdevice can receive the PTT communication can be delivered, the server306 sends an early PING message to the target wireless device 310 beforefinishing other call processing related tasks, such as selection of avocoder and a media host. The PING message is a message used to testwhether a particular network destination on a network is online. Ifthere is no return message from the network destination, then thenetwork destination is either down or unreachable.

The PING message from the server 306 is received and queued at the basestation 308. The base station 308 does not distinguish the PING messagefrom other type of messages. The base station 308 sends a paging signalto the target wireless device 310. When the page response is received bythe base station 308, the base station 308 sets up a data channelbetween the base station 308 and the target wireless device 310. By thetime the data channel is established between the base station 308 andthe target wireless device 310, an announce message would have arrivedfrom the server 306 and queued at the base station 308. When the datachannel is ready, the base station 308 transmits both the PING messageand announce message to the target wireless device 310. After receivingthe PING message and announce message, the target wireless device 310sends acknowledgment messages to both messages back to the server 306.The server 306 receives the acknowledgment messages and grants the floorto the originating wireless device 302 as described above for FIG. 3.

The queuing time 402 for the announce message is greatly reducedaccording to the invention. Because the PING message is dispatched bythe server 306 in the early stage of processing the call requestmessage, the base station 308 can start to page the target wirelessdevice 310 and set up the data channel independently from receiving theannounce message. By overlapping the paging of the target wirelessdevice by the base station 308 and the processing of the call requestmessage at the server 306, the announce message will be queued for ashorter time at the base station 308.

FIG. 5 is a flow chart for a server process 500 according to theinvention. The server receives messages, step 502, from differentwireless devices on a communication network. When a message is received,the server checks the message type, step 504, and the server can processdifferent types of messages, step 508. If the message received is a callrequest message, step 506, from a wireless device requesting a PTTcommunication, the server identifies target wireless devices, step 510.After identifying the target wireless devices, the server checks forcall restrictions for the target wireless devices. If there is no callrestriction, the server sends a PING message to each of the targetwireless devices, step 512, before selecting a vocoder and a media hostfor the PTT communication, step 514. As part of processing the callrequest, the server sends an announce message to the target wirelessdevices, step 516. When an acknowledgment message is received from atarget wireless device, the server will then send a status message backto the originating wireless device granting it the “floor” to make a PTTcommunication.

FIG. 6 is a flow chart for a base station process 600. The base stationreceives messages from a server, step 602, destined to wireless devicesthat are within its geographic area. The base station analyzes themessage's header information and identifies a target wireless device,step 604. After identifying the target wireless device, the base stationsends a paging signal to the target wireless device, step 606. If thetarget wireless device is powered on and in the area, it will send apaging response back to the base station (not shown). After sending thepaging signal, the base station proceeds to initialize a data channelbetween itself and the target wireless device, step 608. After the datachannel is set up, the base station sends the message to the targetwireless device, step 610. The base station will send all the messagesdestined to the target wireless device, step 612, while the data channelis set. When the base station receives acknowledgment messages from thetarget wireless device, the base station forwards them to the server(not shown).

In view of the method being executable on a wireless service provider'scomputer device or a wireless communications device, the method can beperformed by a program resident in a computer readable medium, where theprogram directs a server or other computer device having a computerplatform to perform the steps of the method. The computer readablemedium can be the memory of the server, or can be in a connectivedatabase. Further, the computer readable medium can be in a secondarystorage media that is loadable onto a wireless communications devicecomputer platform, such as a magnetic disk or tape, optical disk, harddisk, flash memory, or other storage media as is known in the art.

In the context of FIGS. 5-6, the steps illustrated do not require orimply any particular order of actions. The actions may be executed insequence or in parallel. The method may be implemented, for example, byoperating portion(s) of the wireless network, such as a wirelesscommunications device or the server, to execute a sequence ofmachine-readable instructions. The instructions can reside in varioustypes of data storage primary, secondary, or tertiary media. The mediamay comprise, for example, RAM (not shown) accessible by, or residingwithin, the components of the wireless network. Whether contained inRAM, a diskette, or other secondary storage media, the instructions maybe stored on a variety of machine-readable data storage media, such asDASD storage (e.g., a conventional “hard drive” or a RAID array),magnetic tape, electronic read-only memory (e.g., ROM, EPROM, orEEPROM), flash memory cards, an optical storage device (e.g. CD-ROM,WORM, DVD, digital optical tape), paper “punch” cards, or other suitabledata storage media including digital and analog transmission media.

While the invention has been particularly shown and described withreference to a preferred embodiment thereof, it will be understood bythose skilled in the art that various changes in form and detail may bemade without departing from the spirit and scope of the presentinvention as set forth in the following claims. Furthermore, althoughelements of the invention may be described or claimed in the singular,the plural is contemplated unless limitation to the singular isexplicitly stated.

What is claimed is:
 1. A method for reducing delay in a push-to-talk(PTT) communication in a wireless communication network, comprising:receiving at a server a first message from an originating wirelessdevice, the first message is a call request message; identifying atleast one target wireless device for the PTT communication in responseto receiving the first message; transmitting a second message, inresponse to receiving the first message, from the server to a basestation to determine whether the at least one target wireless device isonline, the second message having a header with an empty message bodyand being transmitted before an announce message is sent by the serverto the base station; transmitting the announce message from the serverto the base station in response to receiving the first message and aftertransmitting the second message, but before receiving an acknowledgementreceipt of the second message; and receiving at the server, aftertransmitting the announce message, at least one message acknowledgingreceipt of the second message and the announce message from the at leastone target wireless device.
 2. The method of claim 1, further comprisingchecking call limitations for the least one target wireless devicebefore transmitting the second message.
 3. The method of claim 1,further comprising selecting a vocoder and a media host for the PTTcommunication after transmitting the second message but beforetransmitting the announce message.
 4. The method of claim 1, furthercomprising allocating resources by the server to the originatingwireless device after transmitting the second message but beforetransmitting the announce message.
 5. The method of claim 1, wherein thesecond message is a PING message.
 6. A server capable of handlingpush-to-talk (PTT) communications in a communication network andconfigured with software instructions to: receive a call request messagefrom an originating wireless device for a PTT communication-identifyingat least one target wireless device in response to receiving the callrequest message; transmit a testing message to determine whether the atleast one target wireless device is online to a base station beforeallocating resources to the PTT communication; allocate resources to theat least one target wireless device; transmit an announce message to thebase station in response to receiving the call request message and afterallocating the resources to the PTT communication after transmitting thetesting message, but before receiving an acknowledgement receipt of thetesting message; and receive, after transmitting the announce message,at least one message acknowledging receipt of the testing message andthe announce message from the at least one target wireless device. 7.The server of claim 6, wherein the server is further configured withsoftware instructions to check call limitations for the least one targetwireless device before transmitting the second message.
 8. The server ofclaim 6, wherein the server is further configured with softwareinstructions to select a vocoder and a media host for the PTTcommunication after transmitting the second message but beforetransmitting the announce message.
 9. The server of claim 6, wherein theserver is further configured with software instructions to allocateresources to the originating wireless device after transmitting thesecond message but before transmitting the announce message.
 10. Theserver of claim 6, wherein the second message is a PING message.
 11. Anon-transitory computer-readable storage medium having stored thereonmachine-readable instructions configured to cause a server to performoperations comprising: receiving a first message from an originatingwireless device, wherein the first message is a call request message;identifying at least one target wireless device for a push-to-talk (PTT)communication in response to receiving the first message; transmitting asecond message, in response to receiving the first message, to a basestation to determine whether the at least one target wireless device isonline, the second message having a header with an empty message bodyand being transmitted before an announce message is sent by the serverto the base station; transmitting the announce message to the basestation in response to receiving the first message and aftertransmitting the second message, but before receiving an acknowledgementreceipt of the second message; and receiving, after transmitting theannounce message, at least one message acknowledging receipt of thesecond message and the announce message from the at least one targetwireless device.
 12. The non-transitory computer-readable storage mediumof claim 11, wherein the stored machine-readable instructions areconfigured to cause a server to perform operations comprising checkingcall limitations for the least one target wireless device beforetransmitting the second message.
 13. The non-transitorycomputer-readable storage medium of claim 11, wherein the storedmachine-readable instructions are configured to cause a server toperform operations comprising selecting a vocoder and a media host forthe PTT communication after transmitting the second message but beforetransmitting the announce message.
 14. The non-transitorycomputer-readable storage medium of claim 11, wherein the storedmachine-readable instructions are configured to cause a server toperform operations comprising allocating resources by the server to theoriginating wireless device after transmitting the second message butbefore transmitting the announce message.
 15. The non-transitorycomputer-readable storage medium of claim 11, wherein the second messageis a PING message.